This invention relates to biologically pure cultures of microorganisms and, in particular, to biologically pure cultures of microorganisms tolerant to hydrocarbons, alcohols, ethers, ketones or mixtures thereof.
As conventional examples of culturing a microorganism in a medium containing hydrocarbons or their derivatives, there are such many reports as of the growing of Nocardia sp. in a medium containing hexane or hexadecane [R. L. Raymond, Appl. Microbial., vol. 15, pp. 857.about.865 (1967], the growing of Bacterium JOB5 in a medium contining cyclopentane or cyclohexane [J. Ooyama, J. W. Foster, Antonie von Leenwenlook, vol. 31, pp. 45.about.65 (1965)], the growing of Pseudomonas sp., Achromobacter sp., and Nocardia sp. in a medium containing benzene, ethyl benzene, toluene or xylene [D. Cleus and N. Walkes, J, Gen. Microbial, vol. 36, pp. 107.about.122 (1964)], etc. can be enumerated. However, these microorganisms are cultured by bringing the same into contact with hydrocarbons which are concentrated low or in the form of steam in any of the above cases because the hydrocarbons generally show toxicity to microorganisms. That is, when the fermentation is carried out by using these hydrocarbons as substrates, it is carried by supplying these compounds in the form of steam so that the compounds may not be brought into contact with microorganisms directly or by maintaining the compounds at low concentration (0.2% or less) at which a toxic effect is not shown. Consequently, in the fermentation using hydrocarbons as substrates, there are problems not only of low productivity but also of operation because of the difficulty in adjusting the substrates to low concentration. Furthermore, in case of using slightly water-insoluble substances, there is a disadvantage that the productivity becomes low in the microbial reaction owing to the low solubility of the substances.